Larvicidal and Ovicidal Effects of <i>Origanum majorana</i> Essential Oil on <i>Culex pipiens</i> Mosquito

This study tested Origanum majorana essential oil, at different concentrations (3, 5, 10, and 20 μl/ ml), on Culex pipiens larvae and eggs over 24 and 48 hr. The LC50 values were 5.23 μl/ ml at 24 hr and 3.76 μl/ ml at 48 hr, while the LC90 values were 11.44 μl/ ml at 24 hr and 20.89 μl/ ml at 48 hr. These results indicate the essential oil's significant larvicidal effect, although it showed limited ovicidal activity with only a 12.54% to 19.36% reduction in egg viability. These findings suggest that Origanum majorana could be a sustainable alternative to chemical pesticides for mosquito control.